yashsingh1/xdaforums huggingface dataset:
[Nook Color General] angomy:
Thanks a lot for clarifying, I will try it out now that I know I can opt out of the install.

Edit: Ran CrystalDiskMark for 16GB class 4 Sandisk card vs internal nook storage via USB storage mode:

Sandisk 16GB class 4 (non-Ultra+)

Sequential Read : 20.003 MB/s

Sequential Write : 3.086 MB/s

Random Read 512KB : 20.113 MB/s

Random Write 512KB : 1.372 MB/s

Random Read 4KB (QD=1) : 5.143 MB/s [ 1255.7 IOPS]

Random Write 4KB (QD=1) : 0.594 MB/s [ 145.1 IOPS]

Random Read 4KB (QD=32) : 6.019 MB/s [ 1469.4 IOPS]

Random Write 4KB (QD=32) : 0.574 MB/s [ 140.1 IOPS]

Nook internal:

Sequential Read : 19.970 MB/s

Sequential Write : 3.937 MB/s

Random Read 512KB : 20.634 MB/s

Random Write 512KB : 2.173 MB/s

Random Read 4KB (QD=1) : 4.905 MB/s [ 1197.5 IOPS]

Random Write 4KB (QD=1) : 1.106 MB/s [ 270.0 IOPS]

Random Read 4KB (QD=32) : 4.446 MB/s [ 1085.4 IOPS]

Random Write 4KB (QD=32) : 1.116 MB/s [ 272.4 IOPS]
[Nook Color General] LBN1:
UPDATE: Switched to Sandisk Class 4 16gb card; Had to do a clean install from the ground up with the Size-agnostic instructions. Crystal disk mark does benchmark this faster than my Kingston Class 4 16gb card on the random write test, and now Quadrant runs flawlessly without the hangup on the I/O write test (though score is about the same).
[Nook Color General] robot8:
Now it isn't still taking 1~2 mins on the i/o r/w tests right? :)

Try a re-boot, make sure CM7 settles down. Close all unnecessary running apps and notifications. Set your max cpu, then set to "Performance". Now run Quadrant and see what you get.
[Nook Color General] noblerinthemind:
I replaced my 4gb class 4 PNY with the Sandisk 8gb Class 4 - I don't know if I'd quite say night and day, but pretty close. Much much better. I've even got PSX4droid running. It's not running as smoothly as how I've seen iPads run (no worries, I'm not an Apple fan), but still pretty good considering it's supposed to be an ebook reader. I feel like it was a little quicker when it was stock 1.2 and responded a little better but maybe I'm imagining. I haven't compared the two which should be easy enough. One or two FCs but I think that had to do with the set-up, otherwise stable.

Thanks again!
[Nook Color General] robot8:
Are you on an OC kernel? It's pretty smooth running on my setup @ 1.3Ghz.
[Nook Color General] LBN1:
Correct - the I/O test now just takes the "normal" few seconds! With the 1.1 kernel getting about 1700 + on Quadrant. All in all, pleased with the Sandisk card.
[Nook Color General] bonmot1893:
I was about to throw in the towel on CM7 (I bought my NC last week and immediately ran the size-agnostic uSD card installation w/the latest CM7 nightly).

I had been trying a Kingston 8gb Class 4 card, and it was nearly unusable. Clicking a selection in a dialog box sometimes took 5 or more seconds to respond, making it incredibly frustrating. In addition, 2 megabyte downloads took hours to retrieve. It was absurd.

Fortunately, I picked up a Sandisk 8GB Class 4 the next day, and the difference was substantial. The speed increase was astounding, making it very usable and even zippy at times. I have since ditched the 8GB for a 16 GB Sandisk class 4 (imaged from the 8GB and Gparted to expand partition 4). It is equally fast, I think.

My advice -- don't even bother with any brand other than Sandisk unless you're using it as a straight-up media card.
[Nook Color General] residentorca:
I reported earlier having mixed results with a variety of SD card. I decided to move CM7 to internal and have been very pleased with the performance. It's much better than any of the 6 different SD cards I tried.
[Nook Color General] a.fenderson:
microSD card (and reference device) benchmarks, round 3

(See Round 1 and Round 2 from earlier in this thread.)

Benchmarks were done with CrystalDiskMark 3.0.1, on an internal card reader connected to mobo usb pin headers: I had x264 CLI running during encode phase, utilizing 100% on both cores but at "low" thread priority. Based on testing in round 2, this doesn't seem to affect I/O systems to any significant degree. I did 5 runs per test, with a 50MB file size--everything else was left at default.

SanDisk 8GB Class 4 microSDHC

card history: brand new, first use

card origin: http://www.amazon.com/gp/product/B001B1AR50 (seller: Digital Media Source) (listed as Class 2, received Class 4)

Sequential Read : 4.111 MB/s
Sequential Write : 3.362 MB/s
Random Read 512KB : 4.072 MB/s
Random Write 512KB : 2.955 MB/s
Random Read 4KB (QD=1) : 1.030 MB/s [ 251.5 IOPS]
Random Write 4KB (QD=1) : 0.595 MB/s [ 145.2 IOPS]
Random Read 4KB (QD=32) : 0.969 MB/s [ 236.5 IOPS]
Random Write 4KB (QD=32) : 0.596 MB/s [ 145.5 IOPS]

SanDisk 2GB pre-Class microSD

card history: brand new, first use

card origin: http://www.amazon.com/gp/product/B000JLP5UK (seller: CTCStore) (listed as retail package and received thus)

Sequential Read : 4.552 MB/s
Sequential Write : 2.980 MB/s
Random Read 512KB : 4.556 MB/s
Random Write 512KB : 1.078 MB/s
Random Read 4KB (QD=1) : 2.146 MB/s [ 523.9 IOPS]
Random Write 4KB (QD=1) : 0.326 MB/s [ 79.7 IOPS]
Random Read 4KB (QD=32) : 2.165 MB/s [ 528.6 IOPS]
Random Write 4KB (QD=32) : 0.269 MB/s [ 65.7 IOPS]
[Nook Color General] HarryCz:
Hi,

I'm getting my nook next week, and I'm trying to pick an SD for it. I initially wanted an 8GB Class 6 Adata, but they're quite difficult to get a hold of in the UK.

I'm torn between a SanDisk Class 4 and a Samsung Class 6. Both are 8GB.

Anyone got any experience with Samsung or should I still to the tried and tested SanDisk?

edit: I managed to find somewhere with a Class 6 Adata, so that's still an option.

Any advice would be much appreciated.
[Nook Color General] jhitesma:
Glad I saw this thread last week. When I first got my NC I went out and scoured all my local stores to try and find the fastest uSD's I could. My search did not go well. Our Best Buy (literally the worlds smallest Best Buy) didn't have ANY at all. Our Staples didn't have anything other than a few SanDisk of unspecified speed, same with our Wal Marts. Then I hit Target and found a 8G Class 6 Lexar which I snatched up and have been using.

But not very much. It was frustrating. I ran honeycomb and a few CM7 releases but had force closes like mad and the speed was noticeably less responsive than running off internal memory. Was a nice curiosity and I enjoyed being able to taste these other builds without having to permanently install anything, but like the OP I couldn't understand how people could be happy with this as a daily use kind of thing.

Yesterday I finally grabbed a copy of CrystalMark and tested 3 cards I had laying around. A 2G SanDisk with no class marked. An unbranded (probably dane-elec) 4G class 4, and the 8G Lexar Class 6.

Oddly the SanDisk had the fastest sequential speeds. But on the random read/writes all 3 cards were very similar and none had very impressive numbers. The Sandisk did the best though with scores nearing .1 (all the others were slower than 0.01) I didn't have much hope for it not being as quick as the others I've seen reported here but gave it a try and dropped CM7 on it.

Wow. What a world of difference. I've only had 2 force closes and honestly I suspect the app in question more than anything for that. The UI is much snappier and more responsive - everything is greatly improved. It feels just like I assume running off the internal would!

So even though my speeds didn't test out as quick as others in this thread the SanDisk card did perform better than any of the others despite not really looking that much better on paper when comparing the benchmarks.

I'm sold. Next paycheck I'm picking up a 8G SanDisk even if it doesn't have a speed rating.
[Nook Color General] Awats:
I started with Patriot Class 4 2GB and 8GB and had tons of problems. It wasn't until this thread that I decided to consider the SD card as maybe being the problem. I had tons of FC, lockups, delays, etc. and lord help you if you overclocked.

So, I grabbed a 2GB Sandisk Class 4. Bingo. All problems gone! I then bought a 16GB Class 4 Sandisk. Still works like a dream.

All of the problems I had were related to the SD card. If I can get a Sandisk Class 4 32GB cheap, I will give that a try.

I am running CM7 7.0.3 overclocked at 1300Mhz from the SD card and have yet to see one FC. If flashing to emmc is faster, there is no need.

I tested the nightly 67 and it works fine too.

Edited: I meant 32GB and not 64GB (which isn't supported.)
[Nook Color General] rhester72:
Bear in mind that 32GB is where microSDHC tops out - 64GB would be microSDXC which the NC doesn't support.

That being said, I've got 32GB, a 16GB, and 8GB SD class 4 cards and all work brilliantly. They should, of course, perform almost identically to eMMC, given that the eMMC chip is indeed a SanDisk 8GB class 4. =)

Rodney
[Nook Color General] a.fenderson:
Will you be running your Android install off the SD card, or just using it for data?

If just data, you'll be fine for most applications.

I benchmarked several brand-new SanDisk cards of varying capacities, and all the >= 4 GB cards were Class 4, but even so it was hit-or-miss: random 4K writes for the 1 and 2 GB cards sucked, the 4 GB card was decent, the 8 GB card was half as fast as the 4 GB, one of the 16 GB cards looked great, and the other had kind of inconsistent results. So even within the same brand (and class rating where applicable), there is a lot of variation, unfortunately. You might look below and narrow your purchasing options down to those combinations of brand, size, and Class whose 4K random writes are shown to be around 1.00 MB/s or better, though really there are two orders of magnitude difference between the truly crappy cards and the best ones, so even cards with 0.1 to 0.9 MB/s 4K random writes might suffice when compared to the 0.0X cards. In general, so far it looks like SanDisk Class 4 and 2 vary between good (~.5 MB/s) and excellent (~1.5 MB/s), though unclassed SanDisk aren't so great.

If running CM7 (etc) off it, my best advice is to test whatever card(s) you do end up buying with CrystalDiskMark and only using it as your boot disk if the 4K random writes are approximately equal to or greater than 1.00 MB/s.

@all: the anecdotal reports of your cards running well are great, but if you have the time, please benchmark your cards with CrystalDiskMark so that we can all get enough data to be more confident in our card purchases. If you're worried about AV warnings when you download, please see this post where I explained what the opencandy component of the installer does and does not do (it's not malware). Also, along with your benchmarks, please provide your evaluation of how well the card runs your ROM, etc, if applicable.

Here's a compilation of the actual benchmarking data thus far in this thread (with the only benchmakred data presented as 4 KB random write w/ QD=32, since this is the only commonality among all posters). It's been sorted (descending) on the write speed column:

POSTER	BRAND	CLASS	CAPACITY (GB)	4 KB RANDOM WRITE QD32 (MB/s)
swoozle	SanDisk	2	8	1.791
a.fenderson	SanDisk	4	16	1.660
a.fenderson	SanDisk	4	16	1.500
robot8	SanDisk	4	8	1.259
chinly43	SanDisk	4	16	1.257
joobu	SanDisk	4	4	1.175
angomy	Nook internal	N/A	N/A	1.116
a.fenderson	Transcend	2	32	1.032
a.fenderson	SanDisk	4	4	0.898
chinly43	SanDisk	2	8	0.616
a.fenderson	SanDisk	4	8	0.596
angomy	SanDisk	4	16	0.574
a.fenderson	SanDisk	N/A	2	0.269
swoozle	Patroit	10	8	0.038
joobu	Lexar	4	8	0.038
swoozle	Transcend	6	8	0.029
joobu	??	N/A	2	0.029
chinly43	SanDisk	N/A	1	0.029
a.fenderson	SanDisk	N/A	1	0.028
robot8	Transcend	6	8	0.018
ExploreMN	Patroit	10	16	0.018
swoozle	Kingston	4	4	0.016
Tnexus	Patroit	10	16	0.014
a.fenderson	Kingston	4	8	0.014
chinly43	Lexar	4	8	0.011
[Nook Color General] Awats:
Thanks Rodney, I should has said 32GB not 64GB.

As for the eMMC being Sandisk, that is a surprise! Is there a belief that eMMC is faster than the SD card? That is the impression I get but like I said, running from SD is plenty fast enough for me at 1300MHz (with the right SD card!)

+1 thanks!
[Nook Color General] Awats:
I asumme CDM is non-destructive? I have stuff loaded on my cards.
[Nook Color General] a.fenderson:
It requires a minimum of 50MB free space to run, and uses only that free space, so yes, it is non-destructive.
[Nook Color General] Awats:
I tested 6 different cards using an HP 6910p notebook and couple of adapters. I ran it a couple of times for each adapter and the results were pretty consistent so I took the fastest of the group.

Here you go (QD-32) Random Writes:

Kodak USB 50 in 1 adapter:

1. Patriot 4GB Class 4 - .006

2. Patriot 4GB Class 4 - .008

3. Sandisk 2GB Class 4 - .093

4. Sandisk 2GB Class 4 - .089

5. Sandisk 16GB Class 4 - .698

6. Sandisk 16GB Class 4 - .767

HP USB to SD Adapter:

1. Patriot 4GB Class 4 - .011

2. Patriot 4GB Class 4 - .010

3. Sandisk 2GB Class 4 - .150

4. Sandisk 2GB Class 4 - .161

5. Sandisk 16GB Class 4 - 1.243

6. Sandisk 16GB Class 4 - 1.131

Then for fun:

HP MMC/SD built-in adapter in 6910p Notebook (daughter board):

1. Patriot 4GB Class 4 - .016

2. Patriot 4GB Class 4 - .011

3. Sandisk 2GB Class 4 - .236

4. Sandisk 2GB Class 4 - .261

5. Sandisk 16GB Class 4 - 1.391

6. Sandisk 16GB Class 4 - 1.284

Assuming there is some relationship between the QD-32 results and how it performs in the Nook, I can see why the Patriots were a problem. On the other hand, I also found out that the USB adapter greatly affects the test.

What's interesting is the consistency between the common mfg/size. I do know I purchased each of these in pairs when they were on sale so maybe they are from the same mfg batch. Dunno, just a PIOOMA guess.

However, the relative difference in the QD-32 results and the non-scientific-anecdotal-seat-of-the-pants performance in the Nook vaguely infer that a faster QD-32 result works better.

A statistical analysis is in order. It would be great to determine if this test does really give you an indication of the SD card's performance when installed in the Nook even if it is limited to using the relative results only from our own test systems.

Special thanks to my wife for being without her phone for 20 minutes. It was tough but she made it through!
[Nook Color General] HarryCz:
Thanks a lot for that. I want to run CM7 off it, so I'll definitely bench it as you've said. Luckily the cards are quite cheap, so if one turns out to be poor, I'll try the other.

Once I've benched whichever I get I'll post it here.
[Nook Color General] chinly43:
Additional results:

NookColor internal (via USB connection): 1.094

Same 16GB Sandisk as before, WHILE IN NOOK, via USB: 0.769
[Nook Color General] a.fenderson:
@Awats: Wow, you're right about the adapter used, based on your data there's up to a 2.5x difference. Well, at least it's not a whole magnitude of order difference. ;-)

In any case, the overall benchmarking compilation I posted may therefore not be all that great a guide. If everyone posting their benchmarks is assumed to be using the same adapter/setup each time unless otherwise stated, though, then the cards benched by each person should still reveal their relative strengths/weaknesses compared against the others posted by the same person: I can still compile and sort by person posting, that should help minimize the differences in adapters and other factors of the benchmarking setup.
[Nook Color General] Awats:
If we can conclude the test is telling us what we think it is, it's still a good test for an individual to determine which of their cards perform the best. That in itself is worth a lot. The data from everyone will also still help determine which cards perform the best even if we can't compare each others results directly.

Good work you're doing here! +1 your way.
[Nook Color General] colorado_al:
My Sandisk cards are also much better at Random read/write than other cards I have tested (by more than a factor of 10! in the same class). I think for running the OS off of SD, Sandisk is the way to go. As far as media storage/playback while running from emmc, not as big an issue.
[Nook Color General] Taosaur:
I'm curious, do the larger sequential reads of higher-class cards translate into better playback of large video files? Do their lower small-block r/w translate to worse app performance, if your OS is on eMMC but you've saved an app to SD?

Any ideas?
[Nook Color General] Taosaur:
So with regards to practical use in the NC, no.

Would it be correct to say, then, that the only benefit of using a higher-class card in the NC would be faster copying of large blocks of data to and from the card? Can we generalize that statement to all Android devices, or would lower-class cards bottleneck the cameras in other devices?
[Nook Color General] rhester72:
You can update the chart to represent the Nook Internal as a SanDisk Class 4 8GB capacity flash chip, as evidenced in the tear-down photos of the device (cross-reference the part number for full specifications, but it's pretty obvious).

It's interesting that the USB bus the SD card slot sits on adds so much latency to writes...I don't know what USB controller is in use, but while I expected some impact, I guess I didn't expect quite that much.

Bear in mind your USB testing of the SD card inside the Nook actually traverses the USB bus twice:

SD card <-> USB bus B <-> CPU <-> USB bus A <-> PC

whereas testing of eMMC looks more like:

eMMC <-> CPU <-> USB bus A <-> PC

All the same, I'm still confused why small-block random write performance affects things so much, given that the Nook (and all Android-based platforms) generally goes to great pains to *avoid* writes to flash (because even wear-levelling can only do so much, particularly with only 8GB of storage total), especially during the boot process. Things like the FCs that have been exhibited on Patriots, etc. don't seem readily explained by write performance, unless I'm missing the painfully obvious.

But in any event, regardless of the underlying cause, it's pretty clear that SanDisk is the weapon of choice in the Nook. It's a real shame they recently made a decision to drop classes from most of their cards (future runs will not have a class printed on the card and will not indicate class on the packaging, and it is unknown what their actual performance will be), which has really raised ire in professional photography circles. I stocked up on class 4s just in case. =)

Rodney
[Nook Color General] byronczimmer:
I can post the benchmarks later (assuming I actually saved them) but the difference between a SanDisk 8GB/4 and a Transcend 8GB/6 is night and day.

When I benchmarked both cards, the difference was about x60, which means that operations that used to take minutes now take seconds.

Thank you for finding this out!

(Need to buy a few more SD 8G/4 cards before Radio Shack ends their sale.)
[Nook Color General] robot8:
Just to add to the CrystalDiskMark 3.0.1 benchmarks:

Transcend Class 6 / 8Gb

Random Read 4KB (QD=1) : 3.371 MB/s [ 822.9 IOPS]
Random Write 4KB (QD=1) : 0.015 MB/s [ 3.6 IOPS]
Random Read 4KB (QD=32) : 4.153 MB/s [ 1013.9 IOPS]
Random Write 4KB (QD=32) : 0.014 MB/s [ 3.4 IOPS]

Sandisk Class 4 / 8Gb

Random Read 4KB (QD=1) : 3.751 MB/s [ 915.8 IOPS]
Random Write 4KB (QD=1) : 1.219 MB/s [ 297.5 IOPS]
Random Read 4KB (QD=32) : 3.609 MB/s [ 881.0 IOPS]
Random Write 4KB (QD=32) : 1.270 MB/s [ 310.0 IOPS]

Card history: Swapped with a friend, my near new Transcend for his brand new Sandisk. He's not sure why I would want to but he's happy, I'm happy.
[Nook Color General] GTT1:
I am beginning to think there is something amiss with these readings and interpretation vs actual results.

I am running CM7.0.3 off an SD card and I have 2 of them a Transcend 8gb class 6 and a Sandisk 4gb class 2. I use the Sandisk to test before putting on my Transcend. I notice no difference in speed or force closes between the 2 cards. I basically use it for reading emails and some web surfing. Watch the occasional video and listen to Jango. I am pretty happy with my performance which is as fast as my laptop when its on wifi. Since updating to CM703 and using 925 speed I have only had 1 forced close.
[Nook Color General] Taosaur:
Could the results have to do with the Sandisks more closely approximating the architecture of the internal storage than other cards? In other words, is performance gained not because of any specific benchmark, but because the card performs as the ROMs expect it to?
[Nook Color General] rhester72:
I'd consider that pretty unlikely. There's nothing about the underlying technical structure of the card that can be gleaned by the system - it appears as simple block-level storage indistinguishable from any other (minus the removal media bit, but that doesn't play a role here - all of the cards in question have the bit correctly set).

Rodney
[Nook Color General] robot8:
True. Nevertheless, with my own personal experience and the general consensus so far, it's a plus to know that what we're all having good performance with is more or less the same Sandisk flash storage as built into the nook. :D

edit: Pic of the SanDisk SDIN4C1 8GB Flash memory module.
[Nook Color General] robot8:
Interesting, I ditched the Transcend due to random glitches which caused me no small amount of grief.

If you're running CM7 off your Transcend CL6/8G now, do try install Pulse and see if it's stable for you. I bet it would be an interesting test.

That's the one app that would reliably FC on me when I was running off a Transcend.

edit: While using the app, try setting up extra feeds, refreshing, editing pages, etc.
[Nook Color General] a.fenderson:
In general, higher Class cards for the NC are good for what you said: faster file transfers to and from the card. I'd hate to generalize to devices with functionality beyond what the Nook provides, though, especially knowing that the ever larger file-sizes and video bitrates that digital cameras/camcorders are writing is essentially what prompted the SD alliance to come up with the Class rating system in the first place. I don't know of any Android devices specifically that take high-bitrate video or can do high-speed burst mode for stills shots, but they likely exist now or soon will.

I see the photos of the teardown later in the thread and elsewhere, but I couldn't find anything equating that device to any particular SD card Class, or even specifying the exact controller and/or RAM type used in the eMMC so that we can look for cards with the same components: could you provide links if possible?

I don't understand it either, and maybe it's not the entire picture, but even given that writes are intentionally minimized, when there's a 100x difference in write speeds between cards, that's bound to cause noticeable differences.

Where did you come across this info?

Looking forward to your benchmark posting.

Speaking of Radio Shack: I guess mine didn't get the memo about the sale. I glanced over their microSD card offerings today, and saw that their SanDisk 4GB cards were $44.95. I guess they haven't updated card prices, well, ever? AT&T store failed, now Radio Shack fails: living in a small town sucks. ;-)

Have you benchmarked the cards with CrystalDiskMark? If not, this could provide some interesting results.
[Nook Color General] chinly43:
Is there any Android software we could use for these kinds of tests? Something similar to CDM, but that we can run directly from our nooks?